Metallographic observation of reduced-scale advanced EPW after high-speed penetration

In order to enhance the structural stability of earth penetration warhead (EPW) in high-speed penetration, the advanced EPW was designed. The performance of the reduced-scale advanced EPW was experimentally studied during the striking velocity between 1130~1650 m/s. The residual projectiles were studied by metallography. It is found that the heat affected zone (HAZ) is distributed around the projectile surface where the projectile and target contact, including the projectile nose and shank. There is no significant HAZ in the area where the projectile and target off contact. It is concluded that the interaction between target and projectile brings HAZ in. On the other hand, there are several adiabatic shearing bands (ASBs) distributed at the projectile nose tip. Although ASB has positive contribution to the projectile mass loss, the influence can be neglected during the experimental striking velocity range due to the rare number of ASB and the limited distribution area. However, ASB may lead to the nonsymmetrical abrasion of penetrator and then decrease the performance of projectile at higher penetration velocity.